1. Field of the Invention
This invention relates to fabric treating compositions, and more particularly to an aqueous, free-flowing concentrate which contains fabric-softening quaternary ammonium compounds, a fatty acid and/or an alkali metal soap thereof, and a combination of solvents to impart immediate water dispersibility to the active substances of the concentrate.
2. Description of the Prior Art
It has long been known that the wearing comfort of fabrics can be improved by applying to them small quantities of cationic compounds, as a result of which a pleasant, soft feel and antistatic properties are imparted to the fabrics. The cationic compounds may be applied before and after the fabrics are worn, for example, in conjunction with washing. The cationic compounds may be applied to the fabric during the washing, rinsing or drying cycles.
The fabric softeners are utilized best when provision is made to ensure that they are absorbed onto the pieces of wash during rinsing. The most effective fabric softeners in terms of their softening power are quaternary, ammonia- or imidazoline-derived ammonium compounds containing at least two long-chain alkyl or alkenyl groups having from 10 to 20 carbon atoms. These compounds, however, are substantially insoluble in water and, for this reason, are added as dispersions to the rinse water. The content of the active substance in these dispersions usually is quite low; with the most common softener dispersions containing only about 5% by weight of softener. This means that a considerable quantity of water, which must be regarded as a diluent, is present in the dispersion during production, packaging, transport, storage and application. Accordingly, there have been many attempts to reduce the amount of water in softener dispersions and to produce more concentrated products.
Towards that end, for example, fabric softeners more soluble in water were developed (German Application No. 22 56 234); also significant quantities of organic solvents were added to the aqueous softener systems (German Application No. 24 59 354); or concentrated emulsions were prepared by introducing intense shear forces into the dispersions at elevated temperature (U.S. Pat. No. 3,954,634); or alkali nitrite or nitrate was added as an anti-gel agent (German Application No. 28 11 152); or the fabric softener dispersions were mixed with non-softening organic diluents, for example, with water-soluble polymers (German Application No. 30 19 076); with oil-like or fatty substances (German Application No. 28 45 562); with cellulose ethers (U.S. Pat. No. 3,920,561); with relatively high molecular weight amides (German Application No. 28 41 076); with long-chain hydrocarbons or amine derivatives (European Application No. 32 267); or with calcium or magnesium salts (German Application No. 29 05 881); or with aluminium salts (German Pat. No. 2,911,198). In some instances, several of these measures were combined (U.S. Pat. No. 3,681,241); also rinse-cycle softeners containing cationic quaternary ammonium compounds were combined with soap in a ratio of from 1:1 to 1:2 (German Application No. 23 52 955).
Unfortunately, these and other dispersions merely resulted in an unsatisfactory increase in concentration of the diluent-containing concentrates, and the added inorganic salts often deposited on the wash itself. These prior art concentrates also have a low flash point which makes them dangerous to handle, or they are difficult to dilute, or, in their diluted state, they have an inadequate softening effect. Additionally, they are not sufficiently fluid for convenient handling.
Accordingly, an object of the present invention is to provide ready-to-use, free-flowing fabric softener concentrates which have a high content of highly active, fabric-softening substances; which are convenient to handle and easy to dilute; which are highly effective in dilute form; and which do not have a low flash point.